I assume with Aux channels you mean BUS - or is there a different thing?

With regard to streaming in a music setup I suggest looking at them as the same thing. From a linguistic point of view they may differ though; you BUS stuff together but the channel you use for dong that is AÚXILLARY.

> > What should I keep in mind to optimize performance (cpu/memory)?
I was wondering if cpu/memory consumption counts only for the active patch or for all patches in the current concert. Can I save cpu/memory by splitting stuff into several patches instead of one?

No, I would say. Because the more you split sounds into parallel channels the more the CPU needs to work. I tend to stick with patches that use as few channels as possible to lower the CPU load. I even moved Mobius from a bus to the stereo output when researching CPU optimization, but I wasn't able to detect less CPU usage when getting rid of bus splits. So I went back to using a bus (on concert level) for Mobius and (right now, I always change setups) a second bus for a TApe Delay plug-in that I work in real-time for dubby stuff.

Generally I put all reverbs, delays and other effects on the input channels strip. This gives the option to use completely different effect setups in each patch. Except for the Tape Delay on the bus, that I actually use very little, I never put any effects on the looper outputs. All effects that the audience hear and experience as "big and wide sounding" are actually recorded into the loops. This gives the option to do glitchy stuff when slicing and dicing, and I never have the time anyway during a gig to kind of "mix the sound" so I do that in the playing as I record the loops.

I'm just telling this about my general concept because it helps to keep the CPU down quite well.